Unravelling the Role of an Aqueous Environment on the Electronic Structure and Ionization of Phenol Using Photoelectron Spectroscopy

Riley, Jamie W.; Wang, Bingxing; Woodhouse, Joanne L.; Aßmann, Mariana; Worth, Graham A.; Fielding, Helen H.

doi:10.1021/acs.jpclett.7b03310

Cited by 41 publications

(33 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ps* state mediated O-H bond fission in the isolated molecule has been extensively studied, both experimentally and theoretically, [5,6,8,10,11,[45][46][47] and recent ultrafast time-resolved studies following near-UV excitation of phenol in aqueous solution have revealed spectral signatures of both phenoxyl radicals and solvated electrons. [48,49] Such findings accord with the earlier theoretical predictions by Domcke and Sobolewski, who showed that the ps* state of phenol is stabilized when bound to a small cluster of water molecules. [45] In contrast to the isolated phenol molecule, the ps* state of the phenol-water cluster is formed by promoting an electron from a phenol-centred p-orbital to a s*-orbital centred on an O-H bond of a complexing H2O molecule.…”

Section: Introductionsupporting

confidence: 90%

The role of 1πσ∗ states in the formation of adenine radical-cations in DNA duplexes

2018

View full text Add to dashboard Cite

Photoinduced damage of DNA is a well-known but still far from fully understood phenomenon. Electronic structure methods are here employed to investigate potential roles of ps* states in initiating photodamage, and ways in which ps*-state driven photochemistry might evolve with increasing molecular complexity. The study starts with the bare 9H-adenine molecule and progresses through to a model double-helix DNA duplex in aqueous solution. Relative to the gas phase, aqueous solvation is predicted to stabilize the 1 ps* states of these systems when exciting at the respective ground state equilibrium geometries, but to have relatively little effect on the asymptotic N-H bond strengths. But the study also re-emphasises the potential importance of rival s*¬p excitations, wherein a solute p electron is promoted to a s* orbital localized on an O-H bond of a complexing H2O molecule, as a route to forming parent radical cations-as have recently been observed following near UV photoexcitation of double-helix adenine-thymine duplexes in water (Banyasz et al., Farad. Disc. 207, 181 (2018)). The subsequent deprotonation of such radical cations offers a rival low energy route to N-H bond fission and radical formation in such duplexes.

show abstract

Section: Introductionsupporting

confidence: 90%

The role of 1πσ∗ states in the formation of adenine radical-cations in DNA duplexes

2018

View full text Add to dashboard Cite

show abstract

“…Fig. 1a shows the absorption spectra computed with phenol solvated by a different number of water molecules, as well as the experimental spectrum 35 in gas phase and in aqueous solution. In order to evaluate the solvatochromic effects, also the computed gas-phase spectrum is included.…”

Section: Resultsmentioning

confidence: 99%

“…The experimental spectrum in aqueous solution has a maximum at 4.59 eV 35,86 while the one in the gas phase possesses few vibronic transitions 35,85 around 4.6 eV (270 mm), indicating that the solvent barely affects the energy-range of the spectra. The calculated spectra show small shifts, depending on the model used, which are within the error of the method.…”

Section: Resultsmentioning

confidence: 99%

“…Recent photoelectron spectroscopy 35 applied to phenol in water, using excitation at 235.5 nm, which corresponds to an energy just above the conical intersection between the pp* and ps* states, indicated the formation of solvated electrons after 150 fs. They were attributed to a direct excitation to the ps* state leading to O-H dissociation by concerted proton-coupled electron transfer.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Solvent reorganization triggers photo-induced solvated electron generation in phenol

Sandler

Nogueira

González

2019

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…A variety of experimental techniques have been developed by the scientists to explore the photodissociation of phenol, such as H Rydberg atom photofragment translational spectroscopy, velocity map ion imaging, high‐resolution time‐of‐flight spectra and multimass ion imaging . Ratzer et al measured the lifetimes of excited states, and observed the increased OH bond, the shortened CO bond and the expanded aromatic ring on electronic excitation.…”

Section: Introductionmentioning

confidence: 99%

Photodissociation of phenol in the adiabatic representation: Tunneling, motions of phenyl ring, and kinetic isotope effects

Ying

Zhao

2018

Int J of Quantum Chemistry

View full text Add to dashboard Cite

The photodissociation of phenol is a prototype of the photoinduced hydrogen detachment reaction. The dissociation rates of phenol through the excited S 1 state are calculated with the quantum instanton method in full dimensionality. The Arrhenius plot of the rates shows that the quantum tunneling dominates the O H bond dissociation at low temperatures. The degrees of freedom of phenyl ring (C 6 H 5 ) play extremely important roles in the dissociation of phenol. Fixing the phenyl ring at the equilibrium geometry can only provide reliable rates between 400 K and 800 K. The motions of phenyl ring have an impact on enhancing the dissociation by lowering the free energy barrier. The larger the amplitudes of the phenyl ring motions are, the more the free energy barrier will be reduced. The dissociation rates of C 6 H 5 OH are much larger than those of C 6 H 5 OD, which is due to the zero-point energy and entropy effects. K E Y W O R D S free energy barrier, kinetic isotope effect, quantum tunneling, rate constant, zero-point energy 1 | INTRODUCTIONThe photodissociation of phenol to produce H and phenoxyl radical is a prototype of photoinduced hydrogen elimination reaction. Because phenol is one of the chromophores in many natural compounds, the investigation of photochemistry of phenol [1][2][3] provides a useful guide to the study of complex biological molecules, such as peptides and DNA bases.A variety of experimental techniques [4][5][6][7] have been developed by the scientists to explore the photodissociation of phenol, such as H Rydberg atom photofragment translational spectroscopy, [8,9] velocity map ion imaging, [10][11][12][13] high-resolution time-of-flight spectra [14] and multimass ion imaging. [15] Ratzer et al. [16] measured the lifetimes of excited states, and observed the increased O H bond, the shortened C O bond and the expanded aromatic ring on electronic excitation. Tseng et al. [15] detected the cleavage of O H bond at 193 nm and 248 nm. Hause et al. [10] showed that the excitation of O H stretching led to the formation of excited state products. Pino et al. [17] clarified the position and substituent effects of phenol. Nix et al. [4] and Ashfold et al. [5,14] reported that the fragmentation of phenol involved nuclear motion on the [1] πσ* potential energy surface.The electronic structure calculations [18][19][20] have revealed that the photodissociation of phenol to produce H and phenoxyl radical involves the three lowest electronic states, 1 ππ, 1 ππ*, and 1 πσ*. The equilibrium structures and the vertical excitation energies of these states have been predicted by several authors at various levels of theory. Lorentzon et al. [21] obtained 27 singlet states in the range of 4.53 eV-7.84 eV by the complete active space perturbation theory to second-order method (CASPT2). Fang [22] characterized the structures of electronic ground and excited states of phenol at the complete active space self-consistent field (CASSCF) level. Sobolewski and Domcke [23] predicted the vertical excitation energies using a...

show abstract

Unravelling the Role of an Aqueous Environment on the Electronic Structure and Ionization of Phenol Using Photoelectron Spectroscopy

Cited by 41 publications

References 27 publications

The role of 1πσ∗ states in the formation of adenine radical-cations in DNA duplexes

The role of 1πσ∗ states in the formation of adenine radical-cations in DNA duplexes

Solvent reorganization triggers photo-induced solvated electron generation in phenol

Photodissociation of phenol in the adiabatic representation: Tunneling, motions of phenyl ring, and kinetic isotope effects

Contact Info

Product

Resources

About